In the field of integrated circuits, the cost of reticles has become a significant portion of the total manufacture cost.
As circuit feature sizes become smaller, the number of pixels in a circuit increases and the cost of making reticles increases. The trend toward system on a chip ASICs and other forms of custom or semicustom chips has caused production runs to decrease in magnitude, so that the cost of a reticle set must be spread over a smaller number of chips sold.
The conventional form of electron beam, in which a single beam traces out the circuit elements while following a raster pattern has a cost structure that increases with the number of pixels.
A number of attempts have been made to employ parallel electron beams, typically limited to a small number (e.g. less than ten) because of the difficulty in providing a high quality magnetic field to provide the conventional demagnification ratio of four. Highly parallel configurations have been discussed, but have the obstacle that providing a way to focus, collimate, etc. the beams takes up space and that conflicts with the goal of putting a number of beams close together.
Attempts to produce massively parallel (meaning more than one thousand beams) systems have not resulted in commercially available systems. One problem that has not been solved in the art is that of adjusting individual beams to compensate for individual variations between beams and for the effects of use on the parameters of a beam, both of which are inherent in all known systems.